Conventionally, a seat slide device for a vehicle described in the Patent Document 1 has been known. This seat slide device for a vehicle includes a lower rail fixed to a floor side of the vehicle and an upper rail slidably engaged with the lower rail and on which a seat of the vehicle is to be attached. This upper rail is formed by a plate shaped first upper rail and a plate shaped second upper rail layered on the first upper rail and a bracket is disposed between the first and the second upper rails, which rotatably supports a metal-made roller which rolls relative to the lower rail. By this structure, the upper rail can be smoothly movable along the lower rail in a front-rearward direction and accordingly, the upper rail can be formed with the length minimum to support the vehicle seat thereon and the lower rail can be formed with the length maximum to be provided to the vehicle floor. Thus, a seat slide device for a vehicle can be realized, which is movable for adjustment with a long adjusting stroke.